An Interpretive History of Thirty-Years (1945-1975) of Weather Modification.

The development of the physical understanding of weather modification and the evolution of statistical and meteorological design criteria for weather modification experiments for the 30-year period (1945-1975) are investigated. Also, social, economic, and legal problems of weather modification are discussed as they affect the above. Graphs are constructed depicting the chronology of reported articles on storm-system (in this paper 'storm-system' refers to attempts to increase rainfall from extratropical cyclones and organized systems of clouds), cold fog, warm fog, hail, and lightning modification. An attempt is made to explain the changes in the number of experiments reported during the description of the evolution of weather modification. The summary of the 30-year period of weather modification is for three 10-year periods. The first decade is shown to be dominated by scientific innovation and dispute. The second decade featured initiation of efforts by meteorologists and statisticians at ending the controversies of the first 10 years. The third decade was marked by increased exchanges of ideas and results of weather modification operations at conferences and symposia and serious investigation into social, economic, and legal ramifications of weather modification. (Author)